Plastic model construction

ABSTRACT

A molded plastic model, such as a model airplane, having a molded plastic body consisting of mating body shells which are mutually joined along adhesively bonded seams, and thin molded plastic skin sections which are applied over and secured to the sides of the body in such a way as to obscure the seams and reinforce the body. An improved molded plastic wing construction is provided for the model airplane.

United States Patent [72] Inventor Leslie Dewitt, Jr.

2434 N. Durlee, El Monte, Calif. 9173 [21 Appl. No. 797,102 [22] FiledFeb. 6, 1969 [45] Patented July 27, 1971 [54] PLASTIC MODEL CONSTRUCTION16 Claims, 8 Drawing Figs.

[52] US. Cl. 46/76 R ...A63h 27/00 [50] Field of Search. 46174, 76, Y79, 82,162,244/117, 119, 126

[56] References Cited UNlT ED STATES PATENTS f 1,572,166 2/ 1926 Smith46/76 1,581,980 4/1926 Pearson 46/76 10/1936 'Selley 46/76 UX 2,186,0511/1940 Walker.. 46/76 X 2,195,695 4/1940 Daniel 46/76 3,395,484 8/ 1968Smith 46/162 3,438,481 4/1969 Durand 206/4533 Primary Examiner-Louis G.Mancene Assistant ExaminerD. L. Weinhold AttarneyBoniard 1. BrownPATENTEU JUL27 19?: 3, 594846 sum 1 0r 2 //v I/EA/TOR LESL/E 05 1 1/07;JR.

PATENTED JUL27 I97! SHEET 2 OF 2 NT) W n W M Z PLASTIC MODELCONSTRUCTION BACKGROUND OF THE INVENTION l. Field of the Invention Thisinvention relates generally to models and more particularly toimprovements in molded plastic models.

As will appear from the ensuing description, at least some features ofthe invention may be utilized to advantage in various types of plasticmodels. However, the invention is concerned primarily with plastic modelairplanes which are capable of flight. For this reason, the inventionwill be disclosed in connection with models of this class.

2. Prior Art A wide variety of plastic model airplanes have beendevised. Such airplanes, however, are most frequently scale models whichare not designed to fly. This inability of such plastic models to flyconstitutes a distinct disadvantage of the prior art in this field andis due, in part, to the weight of the model, and, input, to their pooraerodynamic characteristics.

Another disadvantage of the existing plastic airplane models resides inthe fact that such models are made in many separate pieces which must beassembled and adhesively joined. The plastic cement which is used forthis purpose is actually a solvent which softens or liquifles thesurfaces to be bonded so as to effect fusion of these surfaces when theyare placed in contact. Because of this dissolving action of the cement,it is very difficult to join plastic parts without excessive erosion' ormelting of the parts. This problem of dissolution of the plastic becomesmore acute the thinner the plastic. Accordingly, sheet plastic modelairplanes are generally provided with a substantial wall thickness whichis much too heavy to permit flight. Moreover, cementing plastic parts,such as plastic body shells, to one another with neat seams between theparts is most difficult to accomplish, particularly for youngerchildren. If the seams are not neatly cemented, of course, the finishedmodel will have a very unprofessional appearance.

SUMMARY OF THE INVENTION The present invention provides an improvedsheet plastic model which avoids the above-noted and other disadvantagesof the existing models of this class and, in addition, possesses variousother beneficial features of construction. As noted earlier, theinvention is applicable to a wide variety of plastic models but isconcerned primarily with and will be disclosed in connection with amodel airplane.

In this regard, one aspect of the invention is concerned with providinga sheet plastic model airplane which is capable of flight when poweredwith a rubberband motor or the like. According to this aspect, theinvention provides a model airplane having a thin-walled molded plasticfuselage body consisting of mating shells which may be assembled andcemented at the factory. Applied over and secured to the sides of thisbody are thin lightweight molded plastic skin sections. These skinsections serve the multiple function of covering the body seams,providing the body with a finished professional appearance, andreinforcing the body. According to a feature of the invention, the bodyshells may be provided with abutting seam flanges and/or indentationswhich cooperate with the skin sections to reinforce the fuselage. Thisresults in a molded plastic fuselage which is relatively light in weightand yet sufficiently rigid for flight. According to another feature ofthe invention, the skin sections may be arranged to cushion impact ofthe fuselage with the ground or other object.

Another aspect of the invention is concerned with an improved moldedplastic wing construction for the model airplane. According to thisaspect, the wing is composed of upper and lower moldedplastic panelshaving parametrical regions of abutting contact at which the panels areeasily joined. One of these wing panels, preferably the lower panel,defines a channel-shaped wing spar formation which is cemented to theopposite panel to reinforce the wing. The open side of this sparformation may be closed by a plastic strip to enhance the appearance ofand further reinforce the wing. Theinvention also provides novelregistry meansfor accurately locating the wing relative to thefuselageto permit attachment of the wing to the fuselage and the optimumposition and attitude for flight.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a modelairplane according to the invention with a portion of the fuselagebroken away for clarity;

FIG. 2 is a fragmentary bottom view of the airplane model;

FIG. 3 is an enlarged section taken on line 3-3 in FIG. 1;

FIG. 4 is an enlarged section taken along line 4-4 in FIG. 3;

FIG. 5 is a fragmentary exploded view of a portion of the fuselage andwing of the airplane model;

FIG. 6 is an enlarged section taken on line 66 of FIG. 2; FIG. 7 is anenlarged section taken on line 7-7 of FIG. 2;

and

FIG. 8 illustrates a modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to these drawings,there is illustrated an airplane model 10 according to the inventionincluding a fuselage 12, a wing 14, and a tail assembly 16. The airplanehas a landing gear 18 and a propeller 20 powered by a rubberband 22. Oneimportant aspect of the invention is concerned with the construction ofthe fuselage 12. According to this aspect, the fuselage is composed ofan inner thin-walled molded plastic body 24 and an outer lightweightmolded plastic skin 26. The skin is cemented to the body in such a wayas to reinforce the body and provide the fuselage with a professionalappearance. In this latter regard, an important function ofthe skin 26is to cover and obscure cemented seams and other undesirable surfacefeatures of the fuselage body, as hereinafterexplained.

Referring to the fuselage 12 in greater detail, the inner fuselage body24 is constructed in two mating sections 28, 30 which comprisethin-walled molded plastic shells. These shells have outwardly directedflanges 32 extending longitudinally along the top and bottom sides ofthe shells in their parting plane. Shells 28, 30 are joined to providethe fuselage body 24 by cementing the flanges 32 to one another. In theevent that the present model is to be sold in kit form, the fuselageshells 28, 30 are-preferably assembled and joined at the factory topermit precise alignment of the shells and proper cementing of theirabutting flanges 32. Formed in the sides of the shells are reinforcingindentations 34. These indentations may also provide access openings tothe interior of the fuselage body 24 to facilitate installation of thelanding gear 18 and the rubberband motor 22.

The fuselage skin 26 comprises separate molded plastic seetions 36, 38,40, and 42 which are applied over and cemented to the top, bottom, andsides, respectively, of the fuselage body 24 in the manner illustrated.In this regard, it will be observed that the skin sections are shaped tomatch their respective body sides, such that the adjacent skin sectionshave abutting edges located along the longitudinal edges of the body. InFIGS. 1 through 4, the upper and lower fuselage skin sections 36, 38engage and are cemented along the longitudinal centerlines to the outeredges of the body flanges 32 and along their outer longitudinal edges tothe upper and lower body walls. The side skin sections 40, 42 arecemented to the sidewalls of the fuselage body about the sidewallindentations 34 and along the longitudinal edges of the fuselage body.

It is now evident, therefore, that the fuselage skin 26 serves the dualfunction of covering the cemented seams, i.e., flanges 32, and otherundesirable surface features, i.e., indentations 34, of the fuselagebody 24 and reinforcing the body. The fuselage 12 may thus beconstructed of relatively light gauge plastic and yet possesssufficiently high strength and rigidity the body shells 28, 30 and theirabutting flanges 32 provide relatively rigid tubular configurations orsectionsextending lengthwise of the fuselage. The sidewalls of thefuselage are similarly reinforced by the sidewall indentations of thebody shells and the side skin sections. The several fuselage skinsections 36, 38, 40, 42 may be embossed to simulate rivets, win-.

dow edging, and other desirable features of the full-scale aircraft.

HO. 8 illustrates a modification of the invention wherein the upperfuselage skin section 36 (as well as the lower fuselage skin section 38not shown) are spaced from the cemented inner body flanges 32. ln thiscase, the skin sections provide a cushioning action in the event ofimpact of the fuselage with the ground or other object. Another aspectof the invention is concerned with the construction of the wing l4.Referring to FIGS. through 7, it will be seen that the wing isconstructed in two sections 14L, 14R which are essentially mirror orimages of one another. Each wing section has upper and lower moldedplastic panels 44 and 46which are cemented to one another along theedges of the wing sections. The lower wing panel 44 has an upwardlyprojecting channel-shaped spar formation 48 which seats against and iscemented to the upper wing panel 46. The lower open side of the sparformation is closed by a plastic strip insert 50 which is cemented inplace. The wing sections 14R, 14L thus possess relatively high lateralbending resistance or strength.

As shown in FIG. 5, the lower wing panels 44 extend inwardly beyond theinner edges of the upper wing panels 46 and overlap one another. Theseoverlapping ends of the wing panels have transverse interfitting channelformations 52 which receive the fuselage body flanges 32. Theoverlapping ends of the lower wing panels have additional longitudinalchannel formations 54 which receive projecting rib or lug formations 56on the fuselage body 12. These interfitting flanges, channel formations,and lugs locate the wing sections 14R, 14L relative to one another andto the fuselage. The wing sections are secured to one another and to thefuselage by cementing the contacting surfaces of these parts. Wing 14 iscompleted by an upper center panel 58 which is shaped to bridge the gapbetween and merge smoothly with the upper wing panels 46. This centerwing panel has channel formations 60 along its leading and trailingedges to receive the fuselage body flanges 32. The center panel issecured in position by cementing the contacting surfaces of the paneland the underlying overlapping ends of the upper wing panels 46.

The tail assembly 16 of the airplane includes a rudder 62 and astabilizer 64. Rudder 62 is formed in two mating molded plastic shellswhich are cemented to one another about contacting edges. The undersideof the rudder has an opening for receiving upstanding lugs 66 integrallymolded on the rear ends of the fuselage body shells 28, 30. These lugsserve to locate the rudder relative to the fuselage. The rudder iscemented in place. Stabilizer 64 is composed of two molded plasticpanels of sections 68, 70 (FIG. 7) which are cemented to one anotheralong their contacting surfaces. The upper stabilizing panel 68 has aftplanar portions 72 which project rearwardly of the lower stabilizerpanel 70 to form simulated control surfaces.

The propeller 20 of the airplane has a central shaft 74 which isjournaled in a bearing 76 mounted within the nose of the fuselage 12.The rear end of the propeller shaft is bent to form a hook 78 forconnection to the front end of the rubberband 22. The rear end of therubberband is fixed to a cross-shaft 80 which extends across theinterior of the fuselage body 24, adjacent its aft end and through holesin the body sidewalls. Preferably, the underside of the fuselage isprovided with openings, as illustrated, through which access may be hadto the interior of the fuselage for replacing the rubberband, whennecessary. As already noted, initial installation of the rubberband maybe accomplished through the sidewall openings in the fuselage body 24prior to cementing of the fuselage skin sections 40, 42 to the bodysidewalls.

' The airplane landing gear 18 is conventional and includes a pair ofwheels 82 which are rotatably mounted on the ends of the U-shaped springwire carriage 84. The central connecting portion 86 of this wire wheelcarriage extends through and is secured to the front end of the fuselage12 in any convenient way. A tail skid 88 may be provided at the rear endof the fuselage.

While the invention has been disclosed in connection with a specificphysical embodiment thereof, it is evident that various modifications ofthe invention are possible within the spirit and scope of the followingclaims.

I claim:

l. A model airplane comprising:

a fuselage including a pair of mating molded plastic shells joined toone another along adhesively bonded seams, and

a relatively thin preformed molded plastic skin including separatepreformed molded plastic skin sections applied over and adhesivelysecured to the sides, respectively, of said fuselage, whereby certain ofsaid skin sections cover said seams.

2. A model according to claim 1 wherein:

said seams comprise abutting flanges on said shells which are adhesivelybonded to one another.

3. A model according to claim 1 wherein:

portions of said skin sections are spaced from the outer surface of saidfuselage to cushion impact of said fuselage with another object.

4. A model according to claim 2 wherein:

said spaced skin portions overlie said flanges and said flanges extendoutwardly from said fuselage to said spaced skin portions, and

the-outer edges of said flanges are adhesively bonded to the overlyingspaced skin portions to provide said fuselage with relatively rigidtubular sections.

5. A model according to claim 2 wherein:

said flanges extend along said top and bottom sides of said fuselage,

the lateral sides of said fuselage have reinforcing indentations, and

the lateral sections of said skin covering said lateral fuselage sidesare adhesively bonded to the latter sides about said indentations toprovide said latter sides with substantial rigidity.

6. A wing for a model airplane of the character described comprising:

upper and lower separately preformed molded plastic wing panels havingabutting edge regions adhesively bonded another to form a hollow airfoilsection, and

one of said wing panels being indented from the outside longitudinallyof said wing to define within said airfoil section of channel-shapedspar formation abutting and adhesively bonded to the other wing panel.

7. A wing according to claim 6 wherein:

said spar formation defines a channel in the outer side of said one wingpanel, and

an insert secured within said channel to conceal the latter.

8. A model comprising:

a hollow thin-walled molded plastic inner body including matingpreformed molded plastic shells adhesively joined along connectingseams,

thin-walled preformed molded plastic skin sections applied to theexterior of and adhesively bonded to said body so as to cover said bodyseams; and

at least one skin section having a central portion spaced from theexterior body surface and edge portions contacting and adhesively bondedto said body at opposite sides of said central portion to define withinsaid body a hollow reinforcing tubular section.

9. A model according to claim 8 wherein:

said body shells have abutting outwardly directed adhesively bondedflanges forming said seams and extending from to one said body surfaceto said central portion of said one skin section; and v the outer edgesof said flanges are adhesively bonded to said central skin portion toform a reinforcing rib between said 7 central skin portion and body.

10. A model according to claim 8 wherein:

said central portion of said one skin section is devoid ofsupport fromsaid body between said edge portions of said latter skin section,whereby said central skin portion is yieldable to cushion an impact.

1!. A model according to claim 8 wherein:

said body has at least one inducted recess covered by one skin section,and

said latter skin section is adhesively bonded to said body about saidrecess to form with the latter a reinforcing tubular section.

12. A model airplane comprising:

a hollow thin-walled molded plastic fuselage having upper and lowerwalls and including mating preformed molded plastic shells withoutwardly directed adhesively bonded flanges along the longitudinalcenterlines of said walls,

a hollow molded plastic wing extending across one of said fuselage wallshaving a transverse channel receiving the adjacent fuselage flanges tolocate said wing relative to said fuselage in the longitudinal directionof said wing and the lateral direction of said fuselage, and

said wing and one fuselage wall having additional mating formations forlocating said wing relative to fuselage in the lateral direction of saidwing and the longitudinal direction of said fuselage.

13. A model airplane according to claim 12 wherein:

said mating formations comprise at least one raised rib on said onefuselage wall extending normal to the fuselage flanges and alongitudinal channel in said wing receiving said rib.

M. A model airplane according to claim 13 wherein:

said. wing comprises separate right and left wing sections havingoverlapping thin-walled panels said panel of one wing section seats atone side against said one fuselage wall and said wing panel channels areindented into said latter panel side and form corresponding raisedformations on the opposite side of said latter wing panel, and

said panel of the other wing section has channels receiving said latterraised formations.

15. A model airplane according to claim 14 wherein:

said wing includes a separate cover panel overlying said overlappingwing panels.

16. A model airplane according to claim 12 including:

a relatively thin preformed molded plastic skin including separatepreformed molded plastic skin sections applied to the exterior of andadhesively bonded to said fuselage to cover said flanges.

1. A model airplane comprising: a fuselage including a pair of matingmolded plastic shells joined to one another along adhesively bondedseams, and a relatively thin preformed molded plastic skin includingseparate preformed molded plastic skin sections applied over andadhesively secured to the sides, respectively, of said fuselage, wherebycertain of said skin sections cover said seams.
 2. A model according toclaim 1 wherein: said seams comprise abutting flanges on said shellswhich are adhesively bonded to one another.
 3. A model according toclaim 1 wherein: portions of said skin sections are spaced from theouter surface of said fuselage to cushion impact of said fuselage withanother object.
 4. A model according to claim 2 wherein: said spacedskin portions overlie said flanges and said flanges extend outwardlyfrom said fuselage to said spaced skin portions, and the outer edges ofsaid flanges are adhesively bonded to the overlying spaced skin portionsto provide said fuselage with relatively rigid tubular sections.
 5. Amodel according to claim 2 wherein: said flanges extend along said topand bottom sides of said fuselage, the lateral sides of said fuselagehave reinforcing indentations, and the lateral sections of said skincovering said lateral fuselage sides are adhesively bonded to the lattersides about said indentations to provide said latter sides withsubstantial rigidity.
 6. A wing for a model airplane of the characterdescribed comprising: upper and lower separately preformed moldedplastic wing panels having abutting edge regions adhesively bonded toone another to form a hollow airfoil section, and one of said wingpanels being indented from the outside longitudinally of said wing todefine within said airfoil section of channel-shaped spar formationabutting and adhesively bonded to the other wing panel.
 7. A wingaccording to claim 6 wherein: said spar formation defines a channel Inthe outer side of said one wing panel, and an insert secured within saidchannel to conceal the latter.
 8. A model comprising: a hollowthin-walled molded plastic inner body including mating preformed moldedplastic shells adhesively joined along connecting seams, thin-walledpreformed molded plastic skin sections applied to the exterior of andadhesively bonded to said body so as to cover said body seams; and atleast one skin section having a central portion spaced from the exteriorbody surface and edge portions contacting and adhesively bonded to saidbody at opposite sides of said central portion to define within saidbody a hollow reinforcing tubular section.
 9. A model according to claim8 wherein: said body shells have abutting outwardly directed adhesivelybonded flanges forming said seams and extending from said body surfaceto said central portion of said one skin section, and the outer edges ofsaid flanges are adhesively bonded to said central skin portion to forma reinforcing rib between said central skin portion and body.
 10. Amodel according to claim 8 wherein: said central portion of said oneskin section is devoid of support from said body between said edgeportions of said latter skin section, whereby said central skin portionis yieldable to cushion an impact.
 11. A model according to claim 8wherein: said body has at least one inducted recess covered by one skinsection, and said latter skin section is adhesively bonded to said bodyabout said recess to form with the latter a reinforcing tubular section.12. A model airplane comprising: a hollow thin-walled molded plasticfuselage having upper and lower walls and including mating preformedmolded plastic shells with outwardly directed adhesively bonded flangesalong the longitudinal centerlines of said walls, a hollow moldedplastic wing extending across one of said fuselage walls having atransverse channel receiving the adjacent fuselage flanges to locatesaid wing relative to said fuselage in the longitudinal direction ofsaid wing and the lateral direction of said fuselage, and said wing andone fuselage wall having additional mating formations for locating saidwing relative to fuselage in the lateral direction of said wing and thelongitudinal direction of said fuselage.
 13. A model airplane accordingto claim 12 wherein: said mating formations comprise at least one raisedrib on said one fuselage wall extending normal to the fuselage flangesand a longitudinal channel in said wing receiving said rib.
 14. A modelairplane according to claim 13 wherein: said wing comprises separateright and left wing sections having overlapping thin-walled panels, saidpanel of one wing section seats at one side against said one fuselagewall and said wing panel channels are indented into said latter panelside and form corresponding raised formations on the opposite side ofsaid latter wing panel, and said panel of the other wing section haschannels receiving said latter raised formations.
 15. A model airplaneaccording to claim 14 wherein: said wing includes a separate cover paneloverlying said overlapping wing panels.
 16. A model airplane accordingto claim 12 including: a relatively thin preformed molded plastic skinincluding separate preformed molded plastic skin sections applied to theexterior of and adhesively bonded to said fuselage to cover saidflanges.